Envelope



Jan. 7, 1941. A. H. SWlFT ENVELOPE Filed April 1, 1955 Patented Jan. 7, 1941 UNITED STATES PATENT OFFICE ENVELOPE Application April 1, 1935, Serial No. 14,096

3 Claims.

The present invention relates to envelopes, and particularly to envelopes of the type which do not require moistening of their sealing flaps due to the use of adhesive having the property of sticking, upon contact, to an area coatedwith a similar adhesive without, however, sticking to uncoated portions of the envelopes.

Envelopes. ofthe above indicated character have heretofore been constructed as shown in Gjorup Patent No. 1,768,836 dated July 1, 1930, with corresponding areas of the seal flap and rear wall provided with dry-sealing adhesive, which is brought into contact by folding over the seal flap to close the envelope in the usual manner. How ever, because of the tendency of the gummed areas to adhere to each other upon contact, as when packing or otherwise handling such envelopes prior to sealing, it is necessary to make special provision for preventing inadvertent adhesion; for example, use of strips of paper between the gummed surfaces, as disclosed in the aforementioned patent.

Other envelopes of the above indicated character have also been hereto-fore constructed as shown in Vogel Patent No. 1,944,020 dated January 16, 1934, with extra flaps carrying the drysealing adhesive, which flaps must be folded in a particular manner after completion of the envelope to prevent premature registration of the gummed areas, as when packing or otherwise handling. Obviously, when such an extra seal flap forms part of the rear wall of an envelope, the upper portion of the envelope pocket cannot be completely sealed, owing to the fact that the extra flap is not secured at its ends, thereby making it possible for small articles to work out of the envelope, even aftersealing.

According to the present invention, there is provided an improved dry-sealing envelope which distinguishes from and is an improvement over prior envelopes of the type represented by the aforementioned patents. In an envelope embodying the invention, corresponding areas of dry-sealing adhesive are applied to the inside of the rear envelope wall and to the outside of the seal flap, respectively; consequently, when the seal flap is folded over in either direction, as in packing or otherwise handling the envelope, there can be no premature adhesion of the gummed areas. Furthermore, the envelope can be quickly and completely sealed by merely tucking the seal flap inside to engage its gumming with the rear wall gumming, the resulting adhesion between the gummed areas being such as to effectively prevent any surreptitious opening of the envelope. The above and other advantageous features of the invention will hereinafter more fully appear from the following description taken in connection with the accompanying drawing, in which-:2

Fig. 1 is a plan view of a gummed blank for forming an envelope in accordance with the invention, with a portion of the upper margin of the blank turned back.

Fig. 2 shows the blank of Fig. 1 folded into an envelope.

Fig. 3 is a front view of the envelope, with the seal flap folded, ready for packing.

Fig. 4 is a sectional view along the line 4-4 of Fig. 3, on an enlarged scale.

Fig. 5 is a rear view of the sealed envelope.

Fig. 6 is a sectional view along the line 66 of Fig. 5, on an enlarged scale.

Like reference characters refer to like parts in the different figures.

Referring first to Fig. 1, a suitable blank for forming an envelope in accordance with the invention provides front and rear wall portions I and 2, side flaps 3 and a seal flap 4. Marginal portions of the rear wall 2 and the flap 4, on

opposite sides of the blank, provide parallel bands of gumming 5 and 6 of such character that one gummed. area will adhere to the other gummed area when brought into contact, although neither gummed area will adhere to the material of the blank. The gumming 5 may be in the form of a dispersed rubber solution, or a natural or compounded latex, although other dry-sealing adhesives such as arclor resins or galyptols, either alone or in combination with rubber, may be used.

In the formation of an envelope from the blank of Fig. 1, the side flaps 3 are first folded over along the score lines 3a, after which the rear wall portion 2 is folded over along the score line 2a, as shown in Fig. 2, with its side portions secured to the underlying portions of the side flaps 3 by a suitable adhesive which partially covers the end portions of the dry-sealing adhesive 5 previously applied to the wall 2. The above described folding is the usual practice in the manufacture of envelopes from blanks of the type shown in Fig. 1 and can be performed on existing envelope machines. In the completed envelope shown in Fig. 2 the gumming 5 extends along the inside margin of the rear wall 2 at the mouth of the envelope pocket, while the gumming 6 on the seal flap 4 is on the reverse side of the extended flap, that is the side corresponding to the front of the envelope. It is to be noted in Fig. 2 that the side flaps 3 are so formed that when the rear wall portion 2 has been secured thereto, the flaps do not entirely cover the ends of the upper margin of the rear wall 2 so that the dry-sealing adhesive 5 is exposed inside the mouth of the envelope pocket for substantially the entire length of the seal flap 4.

In packing, or otherwise handling, the completed envelope in advance of using the same, the flap 4 is folded over into engagement with the front wall I of the envelope, as shown in Fig. 3, thereby entirely concealing the gumming 6. With the flap 4 so folded, it is evident from Fig. 4 that the gummed areas 5 and 6 are both completely covered and so are kept free from dust or rubbing which might tend to destroy the effectiveness of the gumming. Furthermore, with the flap 4 folded against the front Wall I, the mouth of the envelope pocket is entirely open, so that the envelope may be readily loaded without making it necessary to lift and turn back the seal flap. If desired, the envelope can be I packed with the seal ilap folded over against the rear wall 2.

When it is desired to use the envelope of Figs. 3 and 4, it is an easy matter to load the same by reason of the readily opened mouth of the pocket; after which the flap 4 is turned over and tucked inside to bring its gumming 6 face to face with the gumming 5 extending along the inside margin of the rear wall 2. Sealing of the envelope is then completely effected by pressing the upper margins of the front and rear walls together, the envelope then appearing as shown in Figs. 5 and 6. With the envelope so sealed, it is obvious that it is impossible for any of its contents to slip out, owing to the complete adhesion along the mouth of the envelope pocket. Furthermore, owing to the tenacity with which the gummed areas 5 and 5 adhere to each other, it is practically impossible to surreptitiously open the sealed envelope, without tearing the same.

From the foregoing, it is apparent that by the present invention there is provided an improved envelope of the dry-sealing type, particularly characterized by the complete sealing of the envelope pocket and the fact that the self-adhering gummed areas are disposed in concealed noncontacting relation in the manufacture of an envelope from a. prepared blank.

I claim:

1. An envelope comprising a front wall, a back wall portion of substantially the same height as said front wall and folded over said front wall, side flaps of less height than said back wall folded in beneath said back wall portion and adhesively secured along their entire length to the side edges thereof, the upper margin of said back wall portion being free between the upper extremities of said flaps adjacent the ends of said margin and having on its unexposed surface a coating of dry-sealing adhesive and a closure flap foldable along one edge of the envelopes front wall and having on its outer surface a complemental coating of dry-sealing adhesive at substantially the same distance from the fold line of said closure flap as the first-mentioned adhesive coating,-said closure flap in the handling and packing of the envelope before use of same, being folded down on one side of the envelope with its dry-sealing adhesive coating insulated by the envelope material from the complemental dry-sealing adhesive coating on the unexposed upper margin of said back wall portion and with said closure flap adapted, for the sealing of the envelope, to be tucked in behind said back wall margin to obtain contact between said dry-sealing adhesive coatings.

2. An envelope comprising a front wall, a back wall portion folded over said front wall, side flaps folded in beneath said back wall portion and adhesively secured along their entire length to the side edges of said back wall portion, the upper margin of said back wall portion having on its unexposed surface a coating of dry-sealing adhesive extending beyond the upper extremities of said side flaps adjacent the ends of said margin, and a closure flap foldable along one edge of the envelopes front wall and having on its outer surface a complemental coating of dry-sealing adhesive at substantially the same distance from the fold line of said closure flap as the first-mentioned adhesive coating, said closure flap in the handling and packing of the envelope before use of same, being folded down on one side of the envelope with its dry-sealing adhesive coating insulated by the envelope material from the complemental dry-sealing adhesive coating on the unexposed upper margin of said back wall portion and with said closure flap adapted, for the sealing of the envelope, to be tucked in behind said back wall margin to obtain contact between said dry-sealing adhesive coatings.

3. In a mailing envelope, the combination of a front wall having an extension above a horizontal top fold line to form a sealing flap; adhesive on the outer or front face of said sealing flap; a back wall extending to a point immediately below the fold line and having the ends thereof secured in place for the full width thereof; and adhesive along the upper edge of the inner face of the back wall, the front flap being folded forwardly with the adhesive section engaging the front face during storage and folded backwardly and tucked in the envelope into engagement with the adhesive on the back wall when it is desired to seal the envelope.

ARTHUR H. SWIFT. 

